What is the gain of a Slim Jim antenna?
Slim Jim antennas have no performance advantage over the conventional J-pole antenna. The approximate gain in the H-plane of the Slim Jim is from 1.5 to 2.6 dBi (-0.6 dBd to 0.5 dBd).
Table of Contents
What is the formula to calculate antenna length?
The Half-Wave Dipole Antenna The most widely used formula to calculate the approximate overall length of wire required for a dipole is: 468 / frequency (MHz) = length of wire in feet.

What is the gain of AJ pole antenna?
The gain is 2.37 dBi at 4 degrees elevation (compared this to 2.69 dBi for a 1/4wl ground plane). This is actually the best feed system for the J-pole!
Should an end fed antenna be grounded?
No. It has nothing to do with a “ground” or “counterpoise” any more than a dipole fed at its center. Feeding the end of a resonant length of wire requires generating a high voltage field.
What is the correct length of an antenna?

The corresponding optimal antenna length should be 0.69/4, which is equal to 0.1725 meters. The above is the relationship between the length of the antenna and the frequency and wavelength. The length of the antenna is directly related to the wavelength of the working frequency.
How long is a Slim Jim antenna?
The Slim is an end-fed folded dipole antenna that has a gain of 6 dbi and a nice low RF take off angle….Additional information.
Weight | 3.5 lbs |
---|---|
Dimensions | 58 × 5 × 2 in |
Length | 58 Inches tall |
Gain | 5 db, 7 degree take-off angle |
Design | End-fed 1/2 wave folded dipole |
What is a Discone antenna used for?
The discone antenna or discone aerial is often used where an omnidirectional wide band or bandwidth RF antenna design is needed. The discone antenna is used for many radio communication applications from radio scanning and monitoring for the commercial or military services to the home scanner enthusiasts.